A wide variety of security access control devices exist today which attempt to control access to secure areas. Security checkpoints at airports include metal detection and various forms of x-ray and scanning capability, however if a person carrying a weapon was determined to pass through such a security checkpoint while knowing they would be instantly detected, they could do so, and until they were apprehended they could use their weapon within the airport. Metal detectors at the entrance to banks will warn if someone carries a gun into a bank, however it will not stop them from doing so.
Many security systems combine identification mechanisms such as cards, fingerprints, or optical scan in order to identify an individual and allow them access. Unfortunately, the perpetrator of the crime is sometimes one normally allowed access to a facility or area, and use of an identification card will not hinder them. In the case of large gatherings such as lecture halls at universities, schools in general, sporting events, and large business facilities, if a person with suicidal tendencies is determined to wreak havoc and destruction upon a large number of people, today's security access devices will not prevent them from entering if they are carrying a weapon and intend to use it.
Therefore, a new security access control device is needed that will not only detect a person carrying a weapon and attempting to pass through an access point, but will absolutely prevent that person from passing if a decision is made to prevent them—that decision often being made automatically. Also, and given the fact that many of the institutions mentioned above normally allow unhindered access into areas where large gatherings occur, it is important that any new security access device allow high traffic flow at peak times while still being capable of stopping a person carrying a weapon.
A form of access mechanism still popular today is that of a revolving door. It provides continuous flow in both directions, and in spite of the fact that entry into a revolving door can be a little intimidating for some people, revolving doors are deemed to be safe, people understand how to use them, and they continue to be designed into new buildings including hotels, banks and airports. As a side benefit, a revolving door minimizes energy loss due to the manner in which air passes through the door.
There are negatives relative to using a conventional revolving door in a security application, and especially in applications where the amount of traffic is substantial. Conventional revolving doors provide a fixed amount of traffic flow, and the level of flow is always equal in both directions. Thus at a time of day when most people will be exiting a facility, a revolving door will have one half of its capacity unutilized, and therefore a conventional revolving door is space-inefficient. In other words, given an entry passageway to a facility or area of a certain width, a conventional revolving door would be wasting half of that width at times of peak flow in primarily one direction.
If a person in a revolving door was detected to be suspect of carrying a weapon, the revolving door would be stopped and possibly reversed, however if another person was simultaneously exiting in the opposite direction within the same revolving door, they would be stuck in the door, or forced to back up.
Full height turnstiles with multiple crossbars can be useful but have similar problems. Only half the width of a conventional turnstile unit is used for passage and the other half is not usable because of the style of construction of these units. Also, because a conventional turnstile is stationary, placing two of them in series in order to stop a detected perpetrator between them creates the requirement for both of them to be closed at the same time, and also that they both should never be open simultaneously. As a result, a person cannot enter such a turnstile complex while the person ahead of them is simultaneously leaving. Thus the use of a conventional turnstile tends to impede the flow of traffic and is space-inefficient in a manner similar to a revolving door.
What is needed is a security access control device that is space efficient, extremely high throughput, and offers great flexibility in directional control, while at the same time will absolutely prevent a person carrying a weapon from entering a secured area. Applicant has identified these, as well as other shortcomings and needs in the current state of the art in coming to conceive the subject matter described and claimed throughout in this patent application.